Consider a community of 10000 households. 5000 rent their housing, 4500 own their own place, and 500 own more than one place. Now outsiders enter the picture and buy property driving up the prices. The 5000 renting households are now in trouble. If rents go up they are squeezed that way. With rent control there are still issues: Their kids are unable to move out, and separations become tricky. For the 4500 it's a mixed bag. They have the same issues with splitting the household, but they also have advantages. They can do a reverse mortgage and live well. Or they call sell and live well elsewhere. For the 500 elite households it's a pure win, they can buy more yachts than before.

> Now outsiders enter the picture and buy property

Buy it from who? Locals. So who gets the money? Locals.

But anyway the point was don’t divide people into insiders and ‘outsiders’.

In the scenarion the 5000 were renting houses from the 500, so probably the outsiders would buy those properties first.

The 500 are also the most likely not to be local or own the land (which means a single sale can convert a low cost apartament building in a mansion).

Also the reverse is possible...